Acoustic waves are generated when a compressible-fluid is exposed to it rapidly varying heat flux along it confining wall. For an enclosure, these waves reverberate and eventually decay. Buoyancy-induced flows generated within an enclosure can be affected by the acoustic waves generated. The interactions of the acoustic waves produced by rapid heating of a wall with the buoyancy-induced flow in air filled rectangular enclosures are investigated numerically. For the present simulations, the bottom wall of the enclosure is heated rapidly with varying heating rates, while the top wall is held at the initial temperature of the air. The vertical walls of the enclosure are considered insulated. The compressible unsteady Navier-Stokes equations are solved by an-explicit flux-corrected transport algorithm for the convection terms and by it central-differencing scheme for the viscous and conduction terms. (C) 2007 Elsevier Ltd. All rights reserved.